tiller drive shaft universal joints needed!

Cord · Aug 17, 2005

I'm having a tough time finding new universal joints for my tiller drive shaft. The joints are metric and have a internal snap ring. Hoye actually suggested that I take the shaft to a drivetrain ship and have them modify it for a more standard joint. I wanted to try here to see if anybody had some suggestions.

larso1 · Aug 17, 2005

The stub joint that came with my 2-pt Yanmar tiller has a 16-spline 30mm end at the tiller and a standard 6-spline 1-3/8" end at the tractor side. I needed to have the intermediate "H" piece removed from the joint in order to use a standard PTO shaft, so I took it to the local brake, clutch and drive-line shop where they charged me $15.00 to remove the middle piece and reassemble the female splined ends and joint together.

Bill

Cord · Aug 17, 2005

But they reused the existing + joints? It's the + that I need to replace.

HGM · Aug 17, 2005

one of the other posts here talked about just replacing the whole shaft with a new unit for Tractor Suply for $50. I think I would go that route if I have problems with mine.

Cord · Sep 27, 2005

Baum Hydraulics was able to special order the odd ball universal joint. They didn't have the exact one, but there was one that was very close. A little modification was required to make it fit. Before you order you'll need to mik your existing cross. Once you have the measurements, these guys were very helpful.

Mickey_Fx · Sep 30, 2005

( The stub joint that came with my 2-pt Yanmar tiller has a 16-spline 30mm end at the tiller and a standard 6-spline 1-3/8" end at the tractor side. I needed to have the intermediate "H" piece removed from the joint in order to use a standard PTO shaft, so I took it to the local brake, clutch and drive-line shop where they charged me $15.00 to remove the middle piece and reassemble the female splined ends and joint together.

Bill )

IMO you do not want to remove the center piece as it is needed to complete the design and make it function as a CV, constant velocity, joint. Without the center piece any time the tiller is at any angle, there will be small changes in velocity that could cause problems. The greater the angle, the greater the change in velocity. Constant RPM and constant velocity are not the same thing. Think of it like an engine, the crank is moving at a constant velocity (speed) but the piston is never moving at a constant speed.

larso1 · Oct 1, 2005

IMO you do not want to remove the center piece as it is needed to complete the design and make it function as a CV, constant velocity, joint. Without the center piece any time the tiller is at any angle, there will be small changes in velocity that could cause problems. The greater the angle, the greater the change in velocity. Constant RPM and constant velocity are not the same thing. Think of it like an engine, the crank is moving at a constant velocity (speed) but the piston is never moving at a constant speed.

That may be for a 2-pt tiller setup, but my tractor has a 3-pt and I needed to convert the 2-pt tiller to use it. If I had left the intermediate piece on it would have flopped around since there is nothing to support the shaft. I think I will need a PTO shaft with a splined slip joint to take the longitudinal movement. Haven't gotten to that point yet, but soon.

HGM · Oct 1, 2005

You dont have a splined slip joint? It needs to move, I have never seen one without a slip joint..

As for the double cardan joint, it acts as an intermidiate shaft to split the U-joint angle and allow for less articulation and wear. You will also get less vibration with that joint.

I might have misunderstood something here about the your situation though.

larso1 · Oct 1, 2005

I'm by no means an expert on tillers and drivelines, but it seems I have encountered special circumstances when converting from a 2-pt to 3-pt configuration. It "seems" that the 2-pt pivots, or rocks up and down in a very short arc along one centerline which originates close to the tiller at the two main (largest) connecting pins, the cardan joint at the tiller's stub shaft, and a fixed bracket at the tractor. When going to a 3-pt the tiller is obviously connected at three attachment points which all sweep up and down together through a longer arc that originates way back at the tractor's lifting arm rock shaft and requires a much longer pto shaft. My 2-pt tiller does have a splined shaft connection at the Cardan joint and that is where it can go through small movements longitudinally toward and away from the tiller as it pivots up and down. But with the 3-pt there will be much more linear movement and the Cardan joint will need to be locked to the tiller shaft (which has a very short splined length) and a longer splined slip length in the pto shaft will be needed. Otherwise the pto shaft would pull off the short stub shaft at the tiller. I hope I'm explaining this right

) I have been wrong before. /forums/images/graemlins/smile.gif Anyway, the intermediate H piece in the Cardan joint will provide an extra joint that is unsupported and will make the pto shaft flop all around. I think the longer arc sweep of the 3-pt will prevent the u-joint at the tiller from exceeding its maximum allowable operating angle. Otherwise, I will need to look at a ball type CV joint from an automotive application, which is an option.

Bill